Straw Type and Nitrogen Fertilization Influence Winter Common Bean Yield and Quality

The common bean grown under straw of intercropped plants improves the cropping environment in no-tillage systems. In addition, nutrient supply from straw could reduce the use of topdressing nitrogen in common bean. Thus, the objective of this work was to evaluate under no-tillage system the effect of straw type and topdressing nitrogen doses in the irrigated common bean productive and qualitative attributes. The experimental design was in randomized blocks arranged in split-plots with four replications. The plots were composed by three straw types from different cropping systems, represented by sole maize, maize-intercropped with brachiaria and maize-intercropped with crotalaria. The subplots consisted of five topdressing N doses applied on common bean 0, 50, 100, 150 and 200 kg ha −1 of nitrogen via urea (coated with polymers). The common bean grown under the straw of maize intercropped with crotalaria showed higher number of pods per plant, grain yield and lower time for maximum grain hydration when compared to those plants grown under the straw of sole maize. Moreover, the crude protein content in the common bean grains was greater when plants were grown under the straw of maize intercropped with crotalaria than the straw of maize intercropped with brachiaria. The agronomic efficiency of common bean was higher when the plants were grown under the straw of maize intercropped with crotalaria in the lowest nitrogen fertilization rate tested (50 kg ha −1 ). Leaf nitrogen content, grain yield, sieve yield and crude protein content in the grain increased with increasing nitrogen availability via topdressing. Therefore, the results suggest that agronomic and qualitative characteristics of common bean are benefited when cultivated on the maize straw combined with crotalaria even reducing up to 50% the requirement of nitrogen fertilization.